ROTTERDAM, Netherlands (AP) -- A day after ensuring his return to the top of the tennis rankings, Roger Federer sealed a place in the final of the ABN AMRO World Tournament by beating Andreas Seppi 6-3, 7-6 (3) on Saturday.

In Sunday's final, the 36-year-old Federer will win his 97th career title if he beats Grigor Dimitrov, dubbed "Baby Fed" early in his career for his style similarities with the Swiss great.

Federer leads their matchups 6-0.

"We have a similar style of play. The more aggressive player, the more steady server is going to ... have the upper hand tomorrow," Federer said.

He will become the oldest person to hold the No. 1 position when the rankings are updated on Monday. It's been more than five years since Federer was last No. 1, and 14 years since he first reached the top spot.

The two-time Rotterdam champion started slowly against Seppi but won the last four games of the first set to win it 6-3. The second set went with serve all the way to the tiebreak, which Federer easily won.

Federer said he was more relaxed on Saturday after achieving his goal of returning to world No. 1.

"Maybe the pressure being gone helped me a little bit," he said.

No. 5-ranked Dimitrov advanced to the final when his semifinal opponent, No. 7 David Goffin, retired after being hit in the left eye by a ball.

Goffin was attempting to reach a powerful forehand by Dimitrov when the ball deflected off the Belgian's racket frame and into his eye. Dimitrov immediately ran around the net to check on Goffin.

The Belgian left the court for treatment and did not return, handing victory to Dimitrov, who was trailing 1-0 in the second set after winning a close first set 6-3.

Dimitrov, 10 years younger than Federer, will be playing for his ninth career title.